1. Field of the Invention
The present invention relates to an input device including an operation substrate on which a proximity sensor detecting a contact position or an access position of an operation body is mounted, and particularly relates to an input device which allows a pressing operation to be performed on an operation substrate to actuate a pressing force sensor.
2. Description of the Related Art
A proximity sensor which detects an operation state by a finger or the like by using change in capacitance or the like is mounted in a personal computer, a portable electronic apparatus, or the like. In addition, recently, there is a pressing force sensor which operates when a pressing operation is performed on an operation portion including the proximity sensor.
In a movable track pad disclosed in U.S. Patent Application Publication No. 2010/0079404, an electrode substrate constituting a proximity sensor is provided on a front surface of a reinforcing plate. An end of the reinforcing plate is connected to a frame via a flexure hinge on an elastic plate. A pressing force sensor such as a tact switch is provided on the lower side of the other end of the reinforcing plate.
When a finger touches the movable track pad, the contact position is detected by the proximity sensor, and when the reinforcing plate is further pressed by the finger, the flexure hinge bends and the pressing force sensor operates.
In a three-dimensional data input device disclosed in Japanese Unexamined Patent Application Publication No. 2007-299043, a rotation axis is set at the center of a touch panel, and contact points are arranged on both sides of the rotation axis, respectively. When a finger touches the touch panel, the position is detected as information on X-Y, and when either of both sides of the rotation axis is further pressed by the finger, the touch panel rotates to come into contact with the contact point, whereby Z-axis operation information is obtained.
In the movable track pad disclosed in U.S. Patent Application Publication No. 2010/0079404, although the end of the reinforcing plate and the frame are connected to each other via the plate-shaped flexure hinge, it is necessary to fix the plate-shaped flexure hinge to the frame by means of a screw or the like such that a portion thereof having a predetermined surface area overlaps the frame. Thus, a support region of a wide surface area is required for fixing the flexure hinge to the frame at a sufficient surface area. In addition, it is necessary to screw the reinforcing plate and the flexure hinge to each other at a plurality of locations, and it is also necessary to screw the flexure hinge and the frame to each other at a plurality of locations. Thus, many screwing locations are needed.
Furthermore, a return operation of the reinforcing plate is set by elastic bending of the flexure hinge. Thus, when the reinforcing plate is pressed at a location away from the movable hinge, the repelling force is small and the operation reaction force is felt to be small. Therefore, normally, in addition to the movable hinge, it is necessary to arrange a reinforcing spring between the reinforcing plate and the frame, and thus the number of parts is increased.
In the three-dimensional data input device disclosed in Japanese Unexamined Patent Application Publication No. 2007-299043, springs for returning the touch panel are arranged on both sides of the rotation axis, and thus the number of parts is increased. In addition, unless the elastic forces of the springs arranged on both sides of the rotation axis agree with each other, there is the possibility that a difference occurs between a reaction force when one side of the rotation axis is pressed and a reaction force when the other side of the rotation axis is pressed. Furthermore, an operation surface cannot be kept in a parallel state when no operation force is applied.